195Pt–31P nuclear spin coupling constants and the nature of the trans-effect in platinum complexes

Abstract

The ¹⁹⁵Pt–³¹P nuclear spin coupling constants, ranging between 1462 and 5698 c./sec., of twenty-five platinum complexes are reported and discussed in terms of the s-component of the platinum–phosphorus bonds. The trans-influence is defined as the tendency of a ligand to weaken the bond trans to itself, and its relation to the trans-effect is considered. It is shown that the high trans-influence of phosphorus is probably due to a σ-bonding mechanism and makes a significant contribution to the high trans-effect of phosphorus ligands. Some ³¹P chemical shifts are reported.